Abstract:
A ground-based radar survey consisting of 35 discrete quad-polarization measurement sites over three field seasons was undertaken on Rutford Ice Stream, West Antarctica. Sites A01 to A10 were collected on 20 January 2017, along a profile orientated perpendicular to the ice flow direction. The 10 sites are located between the central ice flowline and the ice-stream margin along a profile of length 8.5 km with the inter-site spacing decreasing toward the ice-stream margin. Sites B01 to B10 were collected on 05 December 2019, along a profile orientated parallel to the central flowline. The sites were surveyed with the first site 4 km upstream of site A01 and the inter-site distance spacing fixed at 4 km. Sites C01 to C11 were collected on 14 December 2018, and located between sites A01 and A02 at 200 m spacing. Sites D01-D04, collected on 25 January 2019, are downstream of A01 and form a diamond shape with 800 m spacing. At each site, polarimetric radar-sounding measurements were made using an autonomous phase-sensitive radio-echo sounder (ApRES), a frequency-modulated continuous-wave radar. The ApRES has a centre frequency of 300 MHz and a bandwidth of 200 MHz, which results in a range resolution of approximately 40 cm in ice.
ApRES radar data were collected as part of the BEAMISH Project (NERC AFI award numbers NE/G014159/1 and NE/G013187/1).
Keywords:
anisotropy, fabric, ice flow, polarimetry, radar, rheology
Brisbourne, A., Schlegel, R., Jordan, T., & Zeising, O. (2025). Polarimetric radar measurements for the characterization of ice crystal orientation fabric and anisotropic rheology within Rutford Ice Stream, 2016/2017 to 2019/2020 (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/b89672c4-22fb-434a-9197-4da39d26782a
| Access Constraints: | No restrictions apply. |
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| Use Constraints: | Data supplied under Open Government Licence v3.0 http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/. |
| Creation Date: | 2024-05-29 |
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| Dataset Progress: | Complete |
| Dataset Language: | English |
| ISO Topic Categories: |
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| Parameters: |
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| Personnel: | |
| Name | UK Polar Data Centre |
| Role(s) | Metadata Author |
| Organisation | British Antarctic Survey |
| Name | Alex Brisbourne |
| Role(s) | Investigator, Technical Contact |
| Organisation | British Antarctic Survey |
| Name | Rebecca Schlegel |
| Role(s) | Investigator |
| Organisation | University of Tubingen |
| Name | Tom Jordan |
| Role(s) | Investigator |
| Organisation | Univeristy of Bristol |
| Name | Ole Zeising |
| Role(s) | Investigator |
| Organisation | Alfred Wegener Institute for Polar and Marine Research |
| Parent Dataset: | N/A |
| Reference: | Brennan, P. V., Lok, L. B., Nicholls, K., & Corr, H. (2014). Phase-sensitive FMCW radar system for high-precision Antarctic ice shelf profille monitoring. IET Radar Sonar Navigation, 8 (February 2013), https://doi.org/10.1049/iet-rsn.2013.0053. Jordan, T. M., Martín, C., Brisbourne, A. M., Schroeder, D. M., & Smith, A. M. (2022). Radar characterization of ice crystal orientation fabric and anisotropic viscosity within an Antarctic ice stream. Journal of Geophysical Research: Earth Surface, 127, e2022JF006673. https://doi.org/10.1029/2022JF006673. Jordan, T. M., Schroeder, D. M., Castelletti, D., Li, J., & Dall, J. (2019). A Polarimetric Coherence Method to Determine Ice Crystal Orientation Fabric From Radar Sounding: Application to the NEEM Ice Core Region. IEEE Transactions on Geoscience and Remote Sensing, https://doi.org/10.1109/TGRS.2019.2921980. Young, T. J., Martín, C., Christoffersen, P., Schroeder, D. M., Tulaczyk, S. M., and Dawson, E. J.: Rapid and accurate polarimetric radar measurements of ice crystal fabric orientation at the Western Antarctic Ice Sheet (WAIS) Divide ice core site, The Cryosphere, 15, 4117-4133, https://doi.org/10.5194/tc-15-4117-2021, 2021. |
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| Quality: | Data quality allows for analysis of anisotropy within the upper half of the ice column (approximately 1000 m depth). | |
| Lineage/Methodology: | Polarimetric data were acquired in the quad-polarimetric manner as described in Young et al. (2021) but following the antenna layout and rotation scheme presented in apres-quadpol-field-rutford.jpg. The white open-structure (skeleton-slot) antennas were placed 8 m apart at their outside edge, aligned to magnetic North (40 deg E at the time of acquisition), with the transmit antenna at the northern end. For the initial measurements, antenna connectors are aligned pointing towards magnetic East (polarization termed VV). Five measurements were taken at each site, rotating one antenna at a time through 90 deg anti-clockwise (counter-clockwise) around its centre, starting with the transmit antenna. This results in a sequence of five measurements VV-HV-HH-VH-VV with the final VV (termed VV-rotated) in the opposite orientation to the initial VV. Alignment of the flags used to locate and orientate the antennas was done with a magnetic compass with uncertainty of +/- 5 deg. The raw field data are made available here. No data processing has been applied. |
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| Temporal Coverage: | |
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| Start Date | 2017-01-20 |
| End Date | 2019-12-05 |
| Spatial Coverage: | |
| Latitude | |
| Southernmost | -78.17 |
| Northernmost | -77.8 |
| Longitude | |
| Westernmost | -84.55 |
| Easternmost | -83.58 |
| Altitude | |
| Min Altitude | N/A |
| Max Altitude | N/A |
| Depth | |
| Min Depth | N/A |
| Max Depth | N/A |
| Data Resolution: | |
| Latitude Resolution | N/A |
| Longitude Resolution | N/A |
| Horizontal Resolution Range | N/A |
| Vertical Resolution | N/A |
| Vertical Resolution Range | < 1 meter |
| Temporal Resolution | N/A |
| Temporal Resolution Range | N/A |
| Location: | |
| Location | Antarctica |
| Detailed Location | Rutford Ice Stream |
| Sensor(s): |
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| Data Collection: | Radar: ApRES (British Antarctic Survey's Autonomous phase-sensitive Radio-Echo Sounder) - operated with a linear up-chirp from 200 to 400 MHz over the course of 1 s. An ensemble (burst) of 100 chirps was recorded for each polarimetric measurement. |
| Distribution: | |
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| Distribution Media | Online Internet (HTTP) |
| Distribution Size | 1.3 GB |
| Distribution Format | netCDF |
| Fees | N/A |
| Data Storage: | Each measurement site has its own folder containing raw quad-polarized ApRES data. Within each folder are five netCDF data files: VV, HV, HH, VH and VV-rotated. The data files are labelled with the UTC date and time of acquisition as: Survey_YYYY-MM-DD_HHMMSS.nc, e.g. Survey_2017-01-20_175547.nc. Site coordinates, acquisition-time file names and quad-pol configuration are provided in CSV summary table RIS_All_apres-2016-20.csv. Image file apres-quadpol-field-rutford.jpg is a schematic representation of the field acquisition method. |